JPH0623081Y2 - Infrared receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an infrared receiver for remotely controlling electric equipment such as a television using infrared rays.

2. Description of the Related Art FIG. 4 shows a circuit diagram of an infrared receiver. PD is a photodiode that receives infrared rays, 1 is a receiving circuit that receives an electrical signal from the photodiode, R _{1 to} R ₃ are resistors, and C ₁ to
C ₄ indicates a capacitor, respectively.

After receiving the remote control signal by the photodiode PD and converting it into an electric signal, only the desired signal is taken out by the bandpass filter 4 via the amplifier 2 and the limiter amplifier 3,
The reception output is output from the output terminal 8 via the detector 5, the integrator 6, and the hysteresis comparator 7.

FIG. 5 shows a conventional infrared receiver incorporating the above receiving circuit. Reference numeral 10 is a metal case having a through hole 11 through which infrared rays pass, 12 is an IC 13 for the receiving circuit 1, shield plates 14 and 12 are substrates to which a molded photodiode 15 and a capacitor 16 are assembled. Reference numeral 18 denotes an infrared transmitting filter. Reference numeral 19 is a terminal, 20 is a spacer, 21 is a metal plate that closes the opening of the case 10, and 22 is a piece of attachment to another circuit board that is integral with the case 10. The molded photodiode 15 is a chip-shaped photodiode molded with resin. The upper surface of this chip-shaped photodiode is covered with a resin for transmitting infrared rays.
The shield plate 14 is for shielding the receiving IC 13 and the molded photodiode 15.

The infrared light transmitted from the transmitter passes through the through hole 11 and the infrared filter 18, is converted into an electric signal by the molded photodiode 15, and then the output signal which has been amplified and detected by the receiving IC 13 is outputted from the terminal 19. To be done.

Problems to be Solved by the Invention A mold type photodiode is used for the photodiode 15, and capacitors 16 and 17 are large electrolytic capacitors, and a spacer 2 is provided between the substrate 12 and the metal plate 21.
Since 0 is used, there is a problem that the entire shape of the infrared receiver becomes large.

Further, the spacer 20 and the large shield plate 14 are required, and the terminals of the molded phototransistor 15 are required to be bent, so that the assembly becomes complicated.

Further, since it has an infrared ray passing hole and the connecting point between the case 10 and the metal plate 21 is not airtight, the receiving I
There is a problem in that the reliability of the thick film IC printed and formed on the C13 and the substrate 12 deteriorates with time.

Further, since the photodiode is molded and uses a resin for transmitting infrared rays, there is a problem that it is extremely expensive and expensive, and in this case, there is a problem that the infrared ray transmission amount loss is large.

In view of the above points, an object of the present invention is to provide an infrared light receiving device which is easy to assemble, small in size, inexpensive, and highly reliable by hermetically housing a circuit board in a case.

Means for Solving the Problems The present invention solves the above-mentioned conventional problems, and includes a photodiode for receiving an infrared signal, an amplifier for amplifying the signal from the photodiode, a limiter amplifier for extracting a desired signal, and a bandpass. In an infrared receiving device in which a receiving IC including a filter, a detector for detecting a signal, an integrator, and a hysteresis comparator, and a resistor and a capacitor for determining the characteristics of the respective circuit parts are arranged, Such as a bottomed cylindrical metal case sealed with a light transmitting member, an infrared ray transmitting filter attached so as to be in contact with the surface of the light transmitting member, and a plurality of terminals for closing the opening end of the metal case. A metal disc-shaped stem through which a chip is inserted, and the chip-shaped receiving IC and the chip-shaped photodiode are mounted on the upper surface. A capacitor used on the output stage side of the circuit portion is attached to a position below the receiving IC on the lower surface, a plurality of holes are further provided, and the plurality of terminals are inserted and contacted to the plurality of holes. As a result, both ends are bent so as to surround the photodiode between the substrate arranged on the stem, the receiving IC and the photodiode, and fixed to the ground conductive pattern on the substrate by soldering. And a plate-shaped metallic shield plate, and the substrate is disposed in the metal case so that the infrared transmitting filter and the photodiode face each other, and the metal case and the stem form the substrate. An infrared receiver that is sealed and stored.

Action The infrared transmission hole of the case is sealed with a light transmission member, the infrared transmission filter is attached, the chip photodiode surrounded by the circuit element and the shield plate is attached on the circuit board, and this circuit board is hermetically sealed in the case. It is easy to assemble because it is stored in, and it is small in size, cheap and reliable.

Embodiment FIG. 1 is a sectional view of an infrared receiver according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of FIG. 1 is a sectional view taken along the line AA 'when the exploded perspective view shown in FIG. 2 is assembled. Reference numeral 31 is a cylindrical metal case with a bottom, 32 is a metallic disk-shaped stem, 33 is a ceramic substrate, and 41 to 43 are terminals, respectively.

The low-melting glass 48 is fused to the infrared passage hole 47 of the case 31 and the inside thereof, so that the inside and outside of the case 31 of the passage hole 47 are kept airtight. A film-shaped filter 37 that transmits a long wavelength of infrared rays or more is attached to the outer surface of the glass 48. Note that this filter does not need to be a film, but a paste-like material in which a filter member is mixed with a plastic-based resin can be formed by printing with a thick film. Further, it may be formed of other thin films.

Reference numeral 34 is a chip-shaped photodiode, and 35 is a chip-shaped IC for a receiving circuit, which is mounted on the substrate 33. Then, each of these elements is wired to an electrode pattern (not shown) formed by thick film printing on the substrate. Three
Reference numeral 6 denotes a shield plate for electrically shielding the receiving IC 35 and the photodiode 34. This shield plate 36
Has a shape as shown in an enlarged scale in FIG. 3, and a protruding piece 36a extending downwardly from the center thereof is inserted into a narrow groove 37 formed in the central portion of the substrate 33 to be positioned, and the shield plate The shield plate is stably arranged on the substrate 33 by the bent portions 36b and 36c at both ends of 36.

Then, the ground pattern on the substrate and the shield plate 36 are fixed by soldering at three places (not shown). By surrounding the photodiode 34 by the bent portions 36b and 36c at both ends of the shield plate 36, the signal from the receiving circuit is prevented from wrapping around, and the receiving circuit is completely shielded. or,
This shielding effect is also achieved by the protruding piece 36a inserted into the narrow groove 37 of the substrate 34. That is, the electric signal from the capacitor 38 on the lower surface of the substrate 33 is blocked by the protruding piece 36a and has a shield effect.
The reason why the photodiode is shielded from the electric circuit in this way is that the signal flies to the photodiode 34 from a portion (the signal level is high) particularly near the output stage of the receiving circuit 1 shown in FIG. This is because there is a problem that the output level from the device will decrease.

Reference numeral 39 denotes a chip-shaped capacitor, which corresponds to the capacitor C ₁ in FIG. Since the signal level of the capacitor in this part is low, the shield is unnecessary.

Reference numeral 40 denotes a mylar film which is an insulating plate for preventing the heads of the chip capacitors 38 and 39 from touching the metal stem 32.

Next, the assembly process will be described. Passage hole 47 of case 31
A case assembly is one in which the glass 48 and the filter 37 are attached to the. A substrate assembly is one in which each circuit element is mounted on the substrate 33. Terminals 41 to the stem 32
After inserting 43 and assembling the fixed mylar film 40,
The upper ends of the terminals 41 to 43 are connected to the holes 44 to 46 of the board assembly.
Are inserted and connected (by soldering or by using a conductive adhesive) to the case assembly, and these are put in the case assembly and the peripheral portions 31a and 32a of the case 31 and the stem 32 are hermetically sealed by electric welding in a nitrogen atmosphere. As a result, the case 31 is filled with nitrogen gas, and it is possible to realize a highly reliable infrared receiving device which does not deteriorate due to a change with time of each circuit element.

Although the photodiode 34 and the receiving IC 35 are described as using different chips, the present invention is not limited to this, and the photodiode 34 and the receiving IC 35 may be formed on the same chip.

Since a bare chip-shaped one is used for the photodiode 34 and it is not molded with an expensive resin for transmitting infrared rays as in the conventional case, it can be made inexpensive and small in size.

Effect In the infrared receiver according to the present invention described above, the metal case has a bottomed cylindrical shape in which the infrared passage hole is sealed with a light transmitting member such as glass, and the opening end of the metal case is formed by a metallic disc-shaped stem. Since it is closed and sealed, the case can be made strong without protrusions such as corners, and can be a metal case that is highly resistant to external pressure and highly airtight. or,
Since the metal case has a cylindrical shape, if the diameter and height are the same as those of the rectangular parallelepiped shape, the cylindrical case can be reduced in volume by about 10%, and the size can be reduced accordingly. .

Further, in this metal case, since the substrate is sealed and housed by the metal case and the stem, a chip-shaped receiving IC and a chip-shaped photodiode can be used, and a thin, compact and inexpensive infrared light receiving device is obtained. In addition, it is possible to prevent deterioration of each circuit element due to aging, and reliability can be improved.

Further, a chip-shaped receiving IC and a chip-shaped photodiode are mounted on the upper surface of the substrate, and a capacitor used on the output stage side of the circuit portion is mounted on the lower surface below the receiving IC, so that the device Can be made higher in density and smaller in size, and the distance between the photodiode and the capacitor used on the output stage side can be increased to prevent a signal from flying to the photodiode.

Further, since the plurality of terminals inserted through the metal disk-shaped stem are inserted and connected through the plurality of holes provided in the substrate, the substrate can be positioned and the electrical connection between the substrate and the terminals can be performed at the same time.

Further, since the metallic shield plate is plate-shaped, it is thin and small, and since both ends of the shield plate are bent, it can be mounted stably on the substrate. The shield plate can be grounded and fixed at the same time by fixing it to the ground conduction pattern by soldering.

Furthermore, since the photodiode is surrounded by the shield plate having the above-mentioned configuration, it is possible to prevent a signal from sneaking into the photodiode from the receiving circuit. Further, since there are almost no step parts, there are few soldering points, and there are no unnecessary parts such as spacers, there are features such as easy assembly.

[Brief description of drawings]

1 is a sectional view of an infrared receiver according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the infrared receiver of the present invention, and FIG. 3 is a shield plate used in the infrared receiver of the present invention. FIG. 4 is a perspective view, FIG. 4 is a circuit diagram of the infrared receiver, and FIG. 5 is a conventional infrared receiver. 31 ... Case, 32 ... Stem, 33 ... Substrate, 34 ... Chip photodiode, 35 ... Chip receiving IC,
36 ... Shield plate, 37 ... Infrared transmitting filter, 3
8, 39 ... Chip capacitors, 41-43 ... Terminals, 48
... glass.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H04B 10/22 7210-4M H01L 27/14 Z

Claims (1)

[Scope of utility model registration request] 1. A reception comprising a photodiode for receiving an infrared signal, an amplifier for amplifying a signal from the photodiode, a limiter amplifier for extracting a desired signal, a bandpass filter, and a detector, an integrator and a hysteresis comparator for detecting the signal. And an infrared receiving device in which resistors and capacitors for determining the characteristics of the respective circuit parts are arranged, a bottomed cylindrical metal case having an infrared passage hole sealed with a light transmitting member such as glass, An infrared transmitting filter attached so as to be in contact with the surface of the light transmitting member, a metal disc-shaped stem that inserts a plurality of terminals to close the opening end of the metal case, and a chip-shaped upper surface. The receiving IC and the chip-shaped photodiode are attached, and the output stage side of the circuit portion is located at a position below the receiving IC on the lower surface. A capacitor to be used is attached, a plurality of holes are further provided, and the plurality of terminals are inserted into and contact with the plurality of holes, so that the substrate is arranged on the stem, the receiving IC, and the photodiode. And a plate-shaped metallic shield plate, both ends of which are bent so as to surround the photodiode and fixed by soldering to the ground conductive pattern on the substrate, and the infrared ray transmitting inside the metal case. Infrared receiver in which the substrate is arranged so that the filter for use and the photodiode face each other, and the substrate is sealed and housed by the metal case and the stem.